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AOC2019 07 Java
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package se.saidaspen.aoc2019.aoc07; | |
import java.io.IOException; | |
import java.nio.file.Files; | |
import java.nio.file.Paths; | |
import java.util.ArrayList; | |
import java.util.Arrays; | |
import java.util.List; | |
import java.util.concurrent.*; | |
import java.util.stream.IntStream; | |
import static java.util.Collections.swap; | |
import static java.util.stream.Collectors.toList; | |
import static java.util.stream.LongStream.range; | |
public class Aoc07 { | |
private static final long PHASE_MIN = 5L; | |
private static final long PHASE_MAX = 9L; | |
private static final boolean USE_FEEDBACK = true; | |
public static void main(String[] args) throws IOException { | |
Long[] code = Arrays.stream(new String(Files.readAllBytes(Paths.get(args[0]))).split(",")) | |
.mapToLong(Long::parseLong) | |
.boxed() | |
.toArray(Long[]::new); | |
List<List<Long>> permutations = getPermutations(range(PHASE_MIN, PHASE_MAX + 1).boxed().collect(toList()), 0); | |
System.out.println("Maximum thrust: " + permutations.parallelStream() | |
.mapToLong(l -> findLargestThrust(code, l)).max() | |
.orElseThrow(() -> new RuntimeException("Unable to find a maximum value"))); | |
} | |
private static List<List<Long>> getPermutations(List<Long> arr, int k) { | |
ArrayList<List<Long>> permutations = new ArrayList<>(); | |
for (int i = k; i < arr.size(); i++) { | |
swap(arr, i, k); | |
permutations.addAll(getPermutations(arr, k + 1)); | |
swap(arr, k, i); | |
} | |
if (k == arr.size() - 1) { | |
permutations.add(new ArrayList<>(arr)); | |
} | |
return permutations; | |
} | |
private static Long findLargestThrust(Long[] code, List<Long> phases) { | |
try { | |
ThreadPoolExecutor executor = (ThreadPoolExecutor) Executors.newFixedThreadPool(5); | |
List<BlockingQueue<Long>> wires = IntStream.range(0, phases.size() + 1) | |
.mapToObj(c -> new ArrayBlockingQueue<Long>(2)) | |
.collect(toList()); | |
if (USE_FEEDBACK) { | |
wires.remove(wires.size() - 1); | |
wires.add(wires.size(), wires.get(0)); | |
} | |
for (int i = 0; i < phases.size(); i++) { | |
wires.get(i).put(phases.get(i)); | |
executor.execute(new Amp(code, wires.get(i), wires.get(i + 1))); | |
} | |
wires.get(0).put(0L); // Initial Input | |
executor.shutdown(); | |
executor.awaitTermination(1L, TimeUnit.DAYS); | |
return wires.get(wires.size() - 1).poll(10L, TimeUnit.DAYS); | |
} catch (Throwable t) { | |
throw new RuntimeException(t); | |
} | |
} | |
private static class Amp implements Runnable { | |
private final Long[] code; | |
private int pc = 0; | |
private final BlockingQueue<Long> in; | |
private final BlockingQueue<Long> out; | |
private Amp(Long[] code, BlockingQueue<Long> in, BlockingQueue<Long> out) { | |
this.code = Arrays.copyOf(code, code.length); | |
this.in = in; | |
this.out = out; | |
} | |
public void run() { | |
try { | |
do { | |
String cmd = String.format("%05d", code[pc]); | |
int opCode = Integer.parseInt(cmd.substring(3)); | |
if (opCode == /*INPUT*/ 3) { | |
code[code[pc + 1].intValue()] = in.poll(10L, TimeUnit.DAYS); | |
pc += 2; | |
continue; | |
} else if (opCode == /*OUTPUT*/ 4) { | |
long outVal = code[code[pc + 1].intValue()]; | |
out.put(outVal); | |
pc += 2; | |
continue; | |
} | |
Long param1 = cmd.charAt(2) == '0' ? code[code[pc + 1].intValue()] : code[pc + 1]; | |
long param2 = cmd.charAt(1) == '0' ? code[code[pc + 2].intValue()] : code[pc + 2]; | |
if (opCode == /*ADD*/ 1) { | |
code[code[pc + 3].intValue()] = param1 + param2; | |
pc += 4; | |
} else if (opCode == /*MULT*/ 2) { | |
code[code[pc + 3].intValue()] = param1 * param2; | |
pc += 4; | |
} else if (opCode == /*JMP_IF_TRUE*/ 5) { | |
pc = param1 > 0 ? (int) param2 : pc + 3; | |
} else if (opCode == /*JMP_IF_FALSE*/ 6) { | |
pc = param1 == 0 ? (int) param2 : pc + 3; | |
} else if (opCode == /*LESS_THAN*/ 7) { | |
code[code[pc + 3].intValue()] = param1 < param2 ? 1L : 0L; | |
pc += 4; | |
} else if (opCode == /* EQUAL*/ 8) { | |
code[code[pc + 3].intValue()] = param1 == param2 ? 1L : 0L; | |
pc += 4; | |
} | |
} while (code[pc] != 99); | |
} catch (Throwable t) { | |
throw new RuntimeException(t); | |
} | |
} | |
} | |
} |
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